1. Field of Invention
The invention relates to an ink-jet recording apparatus, and more particularly, to an ink-jet recording apparatus wherein ink adhered to a wiper can be surely wiped therefrom with a simple structure and the ink collected from the wiper can be prevented from dripping and scattering.
2. Description of Related Art
An ink-jet recording apparatus is a kind of image forming apparatus that forms an image on a recording medium, such as a recording sheet and an overhead transparency film, by ejecting ink droplets from a plurality of nozzles provided in an ink-jet head. In the ink-jet recording apparatus, ink may adhere to a nozzle surface when ink is ejected or deteriorated ink is purged from the nozzles. If ink droplets are ejected from the nozzles to form an image with the ink adhered to the nozzle surface, the ink droplets may be ejected in an improper direction. This may cause a printing failure. The ink adhered to the nozzle surface may make the recording medium dirty, resulting in a reduction in printing quality. Further, adhesion of paper dust to the nozzle surface may also cause ink to be ejected in an improper direction, thereby decreasing the printing quality.
In order to recover the ink ejecting condition of the ink-jet head and to prevent the recording medium from getting dirt thereon, a wiping operation is performed on the nozzle surface, to remove the ink and paper dust adhered thereon, at regular time intervals or after a purging operation. The wiping operation is performed using an elastic wiper. While the wiper is pressed against the nozzle surface, the ink-jet head is moved so as to be wiped by the wiper to clean the nozzle surface.
As a matter of course, ink wiped from the nozzle surface of the ink-jet head adheres to the wiper after the wiping operation. If a wiping operation is performed using the wiper having the collected ink thereon, the wiper cannot completely wipe off the ink adhering to the nozzle surface. Further, the ink, which adheres to the wiper and has a high viscosity, may be spread over the nozzle surface by the wiping operation. This makes the nozzle surface dirty and causes the nozzles to be clogged with contaminants and ink having high viscosity, thereby causing ink ejection failure. In order to resolve those problems, an ink-jet recording apparatus has been proposed that has a mechanism for cleaning a wiper separately or an ink absorbing member made of a material having absorbency, to remove ink adhering to the wiper. However, with this structure, the ink-jet recording apparatus becomes complicated, resulting in increased production costs for the ink-jet recording apparatus.
U.S. Pat. No. 5,905,513 discloses an ink-jet recording apparatus as described below. In the ink-jet recording apparatus, a printhead includes a pair of wiper cleaning zones located on both sides of a nozzle plate. Each of the cleaning zones includes a plurality of ribs and a plurality of cavities, wherein at least one cavity is formed between adjacent ribs.
A wiper of a maintenance station is pressed against the nozzle plate of the printhead during a maintenance operation to clean excess ink and contaminants, such as paper dust, from the nozzle plate. In turn, the ribs and the cavities cooperate to remove and collect from the wiper the excess ink and contaminants removed from the nozzle plate.
Elevating members are provided immediately adjacent the wiper cleaning zones and between the wiper cleaning zones and the nozzle plate, and serve to lift the wiper from the plane of the surface of the ribs of a first cleaning zone to the plane of the outer surface of the nozzle plate for wiping and then to gently lower the wiper from the plane of the outer surface of the nozzle plate to the plane of the surface of the ribs in a second cleaning zone after wiping the nozzle plate. The outer surface of the ribs carries the wiper over the cavities.
The invention provides an ink-jet recording apparatus wherein ink adhered to a wiper can be further surely wiped therefrom with a simple structure so as not to again adhere the collected ink to the wiper and the ink wiped from the wiper can be prevented from dripping and scattering.
According to one aspect of the invention, an ink-jet recording apparatus includes an ink-jet head, a support member, a wiper, and a wiper cleaning zone. The ink-jet head has a nozzle surface having a plurality of nozzles therein and performs printing on a recording medium by ejecting ink from the nozzles. The support member supports the ink-jet head and reciprocates along the recording medium. The wiper protrudes within a moving path of the nozzle surface of the ink-jet head and wipes the nozzle surface when the support member moves in a first direction. The wiper cleaning zone is provided to the support member upstream of the nozzle wiping direction with respect to the nozzle surface of the ink-jet head. The wiper cleaning zone includes a cleaning wall, a first plane, and a plurality of grooves. The cleaning wall is provided adjacent to the ink-jet head and protrudes from the support member. The first plane is provided proximate the cleaning wall and extends in a direction reverse to the wiping direction. The plurality of grooves are provided in the first plane, at a predetermined distance from each other. In the ink-jet recording apparatus, the wiper does not contact the first plane, but contacts the cleaning wall, when the wiper protrudes within the moving path of the nozzle surface of the ink-jet head. The cleaning zone further includes a second plane inclined between the first plane and the cleaning wall to initially contact the wiper prior to the wiper contacting the cleaner wall.
With this structure, when the nozzle surface of the ink-jet head is wiped using the wiper, first, the wiper is pressed against the cleaning wall in the wiper cleaning zone provided upstream of the wiping direction, in accordance with the movement of the support member. Therefore, ink adhering to the wiper is wiped off by the cleaning wall. Then, the clean wiper is moved toward the nozzle surface to wipe the nozzle surface while pressed against the nozzle surface. The ink wiped from the wiper and collected on the cleaning wall is held in the plurality of grooves formed continuously from the cleaning wall by capillary action. The ink is held in the grooves so as not to touch the wiper, so that the ink will not adhere to the wiper again.